Temperature effects of kelp physiology

Kelp are canopy-forming seaweeds that provide a myriad of resources for associated creatures. Yet, warming events, including global warming, may negatively affect kelp performance. Under the umbrella of the OCEANKELP project that aims to unravel the effect of a range of environmental and biotic processes on the distribution of kelps across continental Portugal, we tested the ability of juvenile sporophytes of two coexisting kelps, Laminaria ochroleuca and Saccorhiza polyschides, to adjust their photosynthesis and respiration to increasing seawater temperatures. L. ochroleuca showed a reduced ability to acclimatize to changing conditions, whereas S. polyschides demonstrated a larger physiological flexibility. These findings are connected with the life-history traits of these species. Additionally, optimum temperatures for the primary production of kelps were assessed, indicating higher values for inter- than subtidal S. polyschides. Our results suggests that, under a warming climate scenario, responses can significantly vary for each species, and that L. ochroleuca is more susceptible to ocean warming than S. polyschides, due to larger acclimatization capacity of the latter. Download the paper from the articles section.